Dr. Connie Sykes, the owner and operator of a lab that tests for sexually transmitted diseases, shows up at Alex Delaware's office and threatens him in the powerhouse opening of bestseller Kellerman's 29th novel featuring the L.A. psychologist (after 2013's Guilt). Sykes leaves Delaware unscathed, for the time being. In one of the author's better plots, flashbacks chart the events that led to the terrifying encounter. A judge impressed by Delaware's objectivity and expertise persuaded him to serve on a court-appointed panel to provide evaluations in child-custody cases. Sykes was a plaintiff in one. Childless, she insisted that her 16-month-old niece be placed in her care, and that the girl's mother, Sykes's own sister, was not a fit parent, but Delaware's assessment proved fatal to her hopes for custody. The aftermath of the office confrontation results in murder. Kellerman's own experience in the field makes him well suited to describe a psychologist's work without either dumbing it down or resorting to excessive jargon. (Feb.)